Belief is key to success. When you believe in something you are inclined to put maximum effort into seeing it come to fruition. If you truly believe with everything in you that you can and will achieve success, your actions will follow. If you don't really believe that you can accomplish your goals, your actions will reflect that. Why would you put in the effort when you don't actually believe what you are working for is possible? If you can cast aside your doubts and instead hold the belief that anything is possible, it will change your life.
True strength is not measured in the number of pounds you can lift or the amount of pull-ups you can do. Rather it is measured in the sheer amount of will and determination you possess.
Indomitable is defined as, "impossible to subdue or defeat." A person may be physically strong, but if they have a weak mind they can be easily defeated.
Time is frequently used as an excuse for why people don't go after their dreams. Who cares if it takes you 6 years to earn that 4 year degree? You are living those 6 years anyway--you might as well spend them chasing your goals. Do you want to look back after those 6 years are over, filled with regret that you kept yourself stuck in the same position, or would you rather be walking across a stage in a cap and gown, knowing that all that time you put in paid off? If taking the time--however long it may be--to work towards your dreams isn't worth it, what is? Little in life is more important than fulfilling your purpose.